code: def _chi2_moment(n, df):
      # (raw) moments of \chi^2(df)
      return (2**n) * gamma(n + df / 2.0) / gamma(df / 2.0)
  
imports: import warnings
  import numpy
  from numpy.testing import assert_equal, assert_raises, assert_allclose
  import numpy.testing
  from scipy.special import gamma, factorial, factorial2
  import scipy.stats
  from statsmodels.distributions.edgeworth import _faa_di_bruno_partitions, cumulant_from_moments, ExpandedNormal
label_desc: Use image node_id 3 for calling a global function with example usage: _chi2_moment(n, df) and returns: unknown